There has been significant research over the past decades on Natural User Interfaces (NUI). NUI includes new gesture-based interfaces that use touch and/or touch-less interactions or the full body to enable rich interactions with a computing device. Although many different touch sensors and 3D input devices have been developed, each is typically optimized for a particular input modality (e.g. touch on surfaces, 3D hand gestures or whole body tracking) and has different strengths and limitations. Two commercially available examples are Leap Motion™ and Kinect®. Leap Motion™ is only able to estimate the positions of fingertips of a hand in-air but is able to operate at high precision. Kinect® provides more flexibility in sensing dense depth maps of arbitrary scenes and tracking the human skeleton, but at a lower precision.
The embodiments described below are not limited to implementations which solve any or all of the disadvantages of known 3D sensing systems.